1，位置。loc=‘upper right’ 或者loc=1這樣設定。還有如下備選項。

             'best':         0,  # only implemented for axes legends
             'upper right':  1,
             'upper left':   2,
             'lower left':   3,
             'lower right':  4,
             'right':        5,
             'center left'
 
:  6,
             'center right': 7,
             'lower center': 8,
             'upper center': 9,
             'center':       10,

　　2，利用bbox_to_anchor這個引數，可以把圖例放在圖外面。見這裡

　　3，設定透明的圖例，見這裡

　　4，設定圖例字型大小，fontsize引數 : int or float or {‘xx-small’, ‘x-small’, ‘small’, ‘medium’, ‘large’, ‘x-large’, ‘xx-large’}，只有這7種調節值。
　　也可以利用prop引數：先定義font1 = {'size': 15}

　　下面這些是他的所有引數。

def __init__(self, parent, handles, labels,
                 loc=None,
                 numpoints=None,    # the number of points in the legend line
                 markerscale=None,  # the relative size of legend markers
                                    # vs. original
 

                 markerfirst=True,  # controls ordering (left-to-right) of
                                    # legend marker and label
                 scatterpoints=None,    # number of scatter points
                 scatteryoffsets=None,
                 prop=None,          # properties for the legend texts
                 fontsize=None,        # keyword to set font size directly

                 # spacing & pad defined as a fraction of the font-size
                 borderpad=None,      # the whitespace inside the legend border
                 labelspacing=None,   # the vertical space between the legend
                                      # entries
                 handlelength=None,   # the length of the legend handles
                 handleheight=None,   # the height of the legend handles
                 handletextpad=None,  # the pad between the legend handle
                                      # and text
                 borderaxespad=None,  # the pad between the axes and legend
                                      # border
                 columnspacing=None,  # spacing between columns

                 ncol=1,     # number of columns
                 mode=None,  # mode for horizontal distribution of columns.
                             # None, "expand"

                 fancybox=None,  # True use a fancy box, false use a rounded
                                 # box, none use rc
                 shadow=None,
                 title=None,  # set a title for the legend

                 framealpha=None,  # set frame alpha
                 edgecolor=None,  # frame patch edgecolor
                 facecolor=None,  # frame patch facecolor

                 bbox_to_anchor=None,  # bbox that the legend will be anchored.
                 bbox_transform=None,  # transform for the bbox
                 frameon=None,  # draw frame
                 handler_map=None,
                 ):